A portable data device (PDT) is one of many types of mobile data terminals (MDTs) that periodically communicate with host devices, such as computers. Generally these MDTs use wired connections, the most common of which are USB connections and connections over a local area network (LAN) such as an Ethernet LAN. Suppliers of mobile data terminals often supply docking cradles which hold the MDTs and have one or more data jacks for plugging in the wired data connections and power jacks or cables with wall plugs to recharge the batteries in the MDTs.
To accommodate the different data protocols, the docking cradles have two or more data input/output jacks and conventionally have a switch so that a user can manually select which jack to use to connect to the MDT.